1. Field of the Invention
This invention relates to a tube unit system such as an ultrasound imaging catheter system for displaying the sectional view of a tubular cavity or determining blood stream with the aid of an inserting part provided with a tube and inserted into the body cavity such as a blood vessel or a vein or an endoscope system for visual observation of the inside of a tubular cavity.
2. Description of the Related Art
The ultrasound imaging catheter system so adapted as to effect display of the sectional view of a tubular cavity by inserting into the body cavity a catheter provided at the leading end side of a rotary drive shaft thereof with an ultrasound transducer has been heretofore known.
This ultrasound imaging catheter system is readied for use by having a connector of the catheter in a sterilized state inserted into a connecting part of an external drive device, i.e. an unsterilized part serving to rotate the drive shaft. Once the connector is joined to the external drive device, therefore, the part of the connector brought into contact with the external drive device is fated to be contaminated. For the purpose of precluding the possibility that the operator's hands will be contaminated by the part of the connector, therefore, the connector and the external drive device which are in a connected state are not allowed to be separated from each other until the manipulation of the catheter is completed.
When the catheter is manipulated in various ways while the connector of the catheter is kept in connection with the external drive device, however, the body of machine or operator possibly rides on the connected parts of the ultrasound imaging catheter and the external drive device and, as a result, brings the problem of compelling the ultrasound imaging catheter to sustain breakage besides the possibility that the delicate operation of the catheter will be obstructed.
When the ultrasound imaging catheter is to be used, it must be first connected to the external drive device and then given a trial run intended to confirm normal operation before it is inserted into the body cavity. When the ultrasound imaging catheter in use is designed for the self-guiding operation which relies on the operator's application of torque to the catheter to produce a motion of the catheter to the neighborhood of the affected part without requiring use of a guide wire, therefore, since this catheter cannot be operated while it is kept in connection with the external drive device, the operator has no alternative but to remove the connector of the catheter from the external drive device subsequently to the confirmation of the normal operation mentioned above and then proceed to operate the catheter. As a means to prevent the operator s hands from being contaminated in this case, the method of covering the connector with a sterilized cap may be used. This method, however, has the problem of entailing a complicated work which is fated to urge deliberation.